1. Technical Field of the Invention
The present invention relates to a gold plate coated stainless material and a method of producing a gold plate coated stainless material.
2. Description of the Related Art
As an electrical contact material such as used for connectors, switches or printed wiring boards, there has conventionally been used a gold plate coated stainless material configured such that the surface of a stainless steel sheet is coated with a gold plated layer.
Usually, in such a gold plate coated stainless material formed with a gold plated layer at the surface, an underlying nickel plating is performed to form an underlying nickel plated layer on the stainless steel sheet before forming the gold plated layer, in order to improve the interfacial adhesion property of the gold plated layer at the surface. In this case, when the gold plated layer is formed on such an underlying nickel plated layer, if defects such as pinholes occur in the gold plated layer, nickel will dissolve from the underlying nickel plated layer thereby to cause delamination of the gold plated layer, which may be problematic.
To overcome this problem, for example, Patent Document 1 (Japanese Patent Application Publication No. 2008-4498 A) discloses a technique of forming a gold plated layer directly on a stainless steel sheet without performing such underlying nickel plating.